1. Field of the Invention
The present invention relates to a chain saw carried by a helicopter to remove tree limbs.
2. Description of Prior Art
Aerial saws for use in forestry are known. The prior art fails to show, however, a hydraulically powered chain saw that is suspended from a helicopter by a non-twist, non-rigid suspension system that is also non-conductive, as taught by the present invention. The use of a chain saw reduces vibrations that can be caused by multiple saw blades as branches are bounced between the blades, while reducing the number of uncut branches. The non-twist suspension system maintains the saw's cutting direction in line with the helicopter's nose, while allowing flexibility to reduce the transmission of vibration to the helicopter.
U.S. Pat. No. 2,707,008, (Bannister) discloses an aerial saw suspended from a helicopter via a cable. U.S. Pat. No. 4,341,017, (Janczak) discloses a hydraulically powered chain saw.
U.S. Pat. No. 4,554,781, (Rogers, deceased) discloses an aerial saw that is suspended from a helicopter on a boom, is powered hydraulically and has a saw landing assist foot. U.S. Pat. No. 4,644,654, (Howe et al.) discloses a powered saw suspended by an elongated flexible means. U.S. Pat. No. 4,815,263, (Hartung et al.) discloses an aerial saw having a number of circular blades and suspended from a helicopter using a boom. U.S. Pat. No. 4,984,757, (Hartung et al.) discloses a trapeze mount for a boom of a helicopter-borne saw. U.S. Pat. No. 5,107,592, (Downey et al.) discloses an overhead suspended tree trimming saw. Canadian Patent No. 729,953 discloses a boom carried chain saw. Canadian Patent No. 2,021,812 discloses a hydraulically operated, helicopter borne, tree trimming saw.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus an aerial chain saw solving the aforementioned problems is desired.